In the rotary printing machine industry it has long been established that the printing cylinder should be backed by a rotating back-up or so-called "impression", cylinder such that the web, or individual sheets, upon which the printing is to be effected, is/are held and supported against the imprinting force of the rotary printing cylinder. Such conventional printing and impression cylinders are disclosed, for example, in U.S. Pat. Nos., 5,154,602, and 5,103,732 which are hereby incorporated by reference.